Apparatus for winding onto a mandrel



p 3, 1970 JEAN-MICHEL GOLDMAN 3,527,424

APPARATUS FOR WINDING ONTO A MANDREL Filed July 1, 1968 v 4 Sheets-Sheet 1 FIG! 4 FLUID jRESSURE Sept. 8, 1970 JEAN-MICHEL GOLDMAN 3,527,424

APPARATUS FOR WINDING ONTO A MANDREL p 1970 JEAN-MICHEL GOLDMAN 3,527,424

APPARATUS FOR WINDING ONTO A MANDREL 4 Sheets-Sheet 5 Filed July 1. 1968 p 1970 JEAN-MICHEL GOLDMAN 3,527,424

APPARATUS FOR WINDING ONTO A MANDREL 4 Sheets-Sheet 4 Filed July 1, 1968 FIG. 6

United States Patent Ofice 3,527,424 Patented Sept. 8, 1970 APPARATUS FOR WINDING ONTO A MANDREL Jean-Michel Goldman, Brunoy, France, assignor to Societe Nouvelle Spidem, Paris, France, a French corporation Filed July 1, 1968, Ser. No. 741,796 Claims priority, applicatizon grance, June 29, 1967,

Int. 01.12.3511 75/28 U.S. Cl. 242-74 11 Claims ABSTRACT OF THE DISCLOSURE This application relates to improvements in apparatus for winding sheet or strip material into a coil form about a power-driven mandrel and, more particularly, to means for causing one surface area of the sheet or strip to be brought into intimate contact with the mandrel and to be wound thereon.

When the sheet or thin strip is to be wound onto the mandrel, it is generally essential to cause the sheet or the strip to adhere to the external wall of the mandrel for a sufficient length of time to enable the total adhesion force resulting therefrom to overcome the various frictional forces by which the sheet or the strip is retained upstream so that no slip occurs on the mandrel.

In the apparatus usually employed for this purpose and which is generally called a belt-type wrapping apparatus, the sheet to be wound is forced into contact with the exterior surface of the mandrel by a belt means which is intended to keep the sheet applied against the mandrel during the initial phase of the winding operation. However, this type of accessory is cumbersome, occupies a relatively large amount of space, and in addition, since the product to be wound is generally a thin metallic sheet, the edge of the sheet bears against the belt, whereby the latter becomes worn and this is more particularly true when the sheet has been cold-hardened with its longitudinal edges then being sharp.

The present invention concerns a new apparatus for winding sheet or strip-like material onto a mandrel and permits the coiling of said material to be achieved without the aforesaid disadvantages.

According to the invention, the oppositely disposed surfaces of the sheet material to be wound are subjected to different pressures, the value of the pressure which is exerted on the inside surface of the sheet always being lower than that exerted on its outside surface. Thus, in accordance with one embodiment of the invention, the higher pressure exerted on the outside surface of the sheet is that of a fluid emanating from a source or a reservoir and being under a superatmospheric pressure with the inside surface of the sheet being subjected only to ambient pressure.

In accordance with still another embodiment of the invention, it is the outside surface of the sheet which is subjected to ambient pressure, while the inside surface thereof is subjected to a negative pressure, said pressure being exerted through apertures or perforations extending from the hollow core of the mandrel radially through the wall thereof.

In both embodiments of the invention, the mandrel on which the winding is effected is situated within an expansible housing comprising substantially complementally formed half portions which are adapted to pivot about a common axis, so as to be able to move laterally away from the mandrel to enable the finished coil to be withdrawn with the housing halves providing between them means defining an opening which forms a longitudinally extending slotted area through which the free end of the sheet or strip to be wound can be introduced.

Further features and advantages of the invention will become apparent in the course of the following description and with reference to the accompanying drawings, which description and drawings relate to two embodiments of the invention and are given purely by way of illustration and having no limiting characteristics on the concept disclosed.

FIG. 1 illustrates an end elevational view of an apparatus constituting a first embodiment of the invention;

FIG. 2 illustrates the apparatus of FIG. 1 in top plan view;

FIG. 3 is a partial sectional view along line II of FIG. 1 with the mandrel removed;

FIG. 4 is a developed view indicating one of the possible patterns of apertures in the wall of the half housings of the apparatus according to FIGS. 1, 2 and 3;

FIG. 5 is a cross-section through the apparatus constituting the second embodiment of the invention taken along plane 5-5 of the following FIG. 6;

FIG. 6 is a section along line 6-6 of FIG. 5; and

FIG. 7 is an auxiliary means to complete the effect of a positive or negative pressure.

Turning now to the embodiment of the invention illustrated in FIGS. 1 to 4, the housing surrounding the mandrel is in the form of two complementally formed separable elements illustrated by way of example as two half casings or portions 1 and 2 which may have any desired external contour but which define a cylindrical internal cavity extending coaxially relative to the mandrel 9, the internal diameter of the cavity being substantially larger than the external diameter of the mandrel 9. The cavity is arranged to be closed in a fluid-tight manner at its oppositely extending two end portions by spaced walls 14 and 15, only the means forming the gap 3 being left open to the atmosphere for the introduction of the leading edge of sheet 4 which is to be wound.

At 5 there is shown the pivoting axis which is common to the two half casings 1 and 2 which may generally be moved laterally away from their operative position as shown in FIGS. 1 and 5 at the end of the winding operation by pivoting in the direction of the arrows 6 and 6a so that the wound coil may be removed.

To one of the half casings and as best shown in FIG. 1 there is provided a cylindrical duct 7 comprising at its free end an annular flange 8 which enables the duct 7 to be connected by means of a flexible conduit to a source of supply which produces a suitable fluid under pressure.

The internal walls 10 and 11 of the two half casings are formed with apertures more or less regularly distributed over the surface area thereof and intended to permit the emission of the fluid under pressure into the central cavity surrounding the mandrel, with the jets of pressurized fluid therefrom all being directed substantially radially toward the mandrel. At 12 there is shown only generally a motor-driven gear reduction unit by which the mandrel is appropriately rotated.

FIGS. 3 and 4 illustrate merely by way of example arrangements of the apertures 13 which are of elongate form and are disposed over the whole surface areas of the cylindrical Walls 10 and 11 as shown.

The apparatus of the first embodiment operates as follows: On being introduced through the means defining the opening or gap 3 into the internal cavity of the expansible housing, the free end area of the sheet or Strip to be wound is urged against the surface of the mandrel by the emission from the first jets of fluid with which it comes into contact. As the sheet or strip is pulled by the mandrel with its end travelling farther into the cavity in the casing, additional fresh jets of fluid to which it is exposed in its passage into said casing constantly maintain it against the mandrel, whereby the surface on which the action of the fluid is exerted, is gradually increased.

When the sheet has completed one revolution about the mandrel and has then begun to be wound upon itself, at which time its leading edge is then engaged under the second layer being formed, the action of the fluid can be exerted on the entire exposed surface area of the sheet metal with the exception of that trailing portion of the sheet which extends toward the inlet gap and through which a portion of the fluid is permitted to escape.

It is also contemplated that either or both portions of the housing may be provided with roller means 16 (FIG. 7) which are urged outwardly away from the casing halves and toward the mandrel to thereby strengthen the force of application to the mandrel. It will be apparent that any suitable spring means 16 may be interposed between the roller means and its carrier means therefor which is associated with the casing elements.

The action of the fluid will be stopped when a sufficient number of layers have been formed around the mandrel, whereby complete adhesion of the sheet to the latter is ensured.

In the second embodiment of the invention illustrated in FIGS. and 6, the casing surrounding the mandrel is in the form of two cylindrical half shells or elements 18 and 19 closed in a fluid-tight manner at its opposite ends by walls 14 and 15 (FIG. 6).

As in the first embodiment disclosed herein, the cylindrical cavity of the expansible housing is coaxial with the mandrel 9 and its internal diameter is substantially larger than the external diameter of the mandrel.

As disclosed earlier in connection with the first embodiment of the invention, the internal cavity communicates with the atmosphere through the longitudinally extending gap 3.

At 16 there is shown a pivot pin which is common to the two half shell portions 18 and 19, which may be oscillated from their operative position at the end of the winding operation by being pivoted in the direction of the arrows 6 and 6a, as explained earlier herein.

The mandrel 9 is fixedly mounted on a hollow shaft 20 which is driven by means of a motor-driven gear reduction unit shown only generally at 12.

The hollow shaft 20 is closed in a fluid-tight manner at its outer end and is arranged to communicate through its other or inner end with an enclosed space, not shown, (see FIG. 6), in which there is provided a more or less high vacuum depending upon the particular characteristics of the sheet or strip to be wound.

Beneath the surface of the mandrel 9 there are provided longitudinally extending channels 21 which are situated at substantially regular intervals along the generatrices of a cylinder concentric with the mandrel, and the diameter of the base of which is slightly smaller than that of the mandrel itself. The two end plates 14 and 15 close all the longitudinal channels 21 in a fluid-tight manner and are suitably perforated as shown in FIG. 6 to permit communication of conduits 22 and 23 (only two shown) with each of the channels 21 and the hollow shaft 20.

Radial orifices 17 extending from each of the longitudinal channels 21 lead to the surface of the mandrel and the pivot pins 1616 together with the supports 24 and 25 maintain the whole apparatus in an operative position.

The apparatus operates as follows: The negative pressure produced in the internal cavity of the hollow shaft 20 is transmitted through the conduits 22 and 23, as previously explained, to the longitudinal channels 21 and thereafter to the radial orifices 17 which are distributed over the entire surface of the mandrel.

As soon as the free end 4 of the sheet or strip to be wound is introduced into the longitudinally extending opening or gap 3, this end portion is brought under the influence of the atmospheric pressure exerted on the outside face thereof and is applied against the mandrel without any counteraction on the inside surface of the sheet which is subjected to a negative pressure.

This action continues in the same way throughout the length of the first turn performed by the end of the sheet metal which is gradually rotated by the mandrel.

As in the preceding example, as soon as the first turn has been looped about the mandrel, the end of the sheet is engaged under the commencing second turn of the material about the surface on which it is then continuously wound to completion of the coil. The vacuum is broken as soon as it is certain that the remainder of the sheet or strip to be wound can be driven without slipping since it henceforth adheres sufficiently to the mandrel.

Although two embodiments of the invention have been depicted and described, it will be apparent that these embodiments are illustrative in nature and that a number of modifications in the apparatus and variations in its end use may be elfected.

What is claimed is:

1. In an apparatus for forming a coil of strip material about a mandrel the combination comprising, a separable housing arranged to surround said mandrel, said mandrel having an outer surface area, elongate means defining an opening in said housing permitting entry of a leading edge portion of a strip of material thereinto, means causing said leading edge portion to be brought into engagement with the outer surface of said mandrel, means for driving the mandrel to wind the strip into a coil thereupon, and means for separating the housing to permit removal of the coil.

2. In an apparatus for forming a coil of strip material as claimed in claim 1, wherein the housing comprises substantially complementally formed separable elements.

3. In an apparatus for forming a coil of strip material as claimed in claim 2, wherein the separable elements comprising said housing are pivotally associated.

4. In an apparatus for forming a coil of strip material as claimed in claim 1, wherein the housing includes oppositely disposed end walls, said end -walls being provided with means adapted to provide closures for said housing.

5. In an apparatus for forming a coil of strip material as claimed in claim 1, wherein said housing includes inner perforate wall portions, said housing being further associated with means furnishing a source of fluid under pressure which when emitted from said perforate wall portions causes the strip to be brought into surface contact with said mandrel.

6. In an apparatus for forming a coil of strip material as claimed in claim 1, wherein the mandrel comprises a hollow perforate body.

7. In an apparatus for forming a coil of strip material as claimed in claim 6, wherein the hollow perforate body of said mandrel is associated with a source of negative pressure.

8. In an apparatus for forming a coil of strip material as claimed in claim 1, wherein the housing includes at least two substantially concave inner wall portions, said wall portions being complemental to the outer surface area of said mandrel.

9. In an apparatus for forming a coil of strip material as claimed in claim 2, wherein at least one of the com- 5 6 plementally formed separable elements is associated with strip to conform to the outer surface of said mandrel means furnishing a source of fluid under pressure. are er mea s. t In an apgaratuls for1forming a coil of strip ma- References Cited erra as c anne m c ann comprising means to cause the surface area trailing said leading edge portion of said 5 UNITED STATES PATENTS strip to conform to the outer surface of said mandrel, 3,127,122 3/1964 ROShkind 242-74 X 11. In an apparatus for forming a coil of strip ma- 3,134,527 5/1964 Willis terial as claimed in claim 10, wherein the means to cause 3326491 6/1967 Bradt et a1 242 74 the surface area trailing said leading edge portion of said 10 NATHAN L, MINTZ, Primary Examiner 

